Larval culture technique and quality control in juveniles of flounder Paralichthys orbignyanus (Valenciennes, 1839) in Argentina

Abstract

Paralichthyds are the most economically important fish in the Southern Atlantic due to their abundance, flesh quality, high market price and increasing fishery demand. In Argentina, the first juvenile mass production of flounder Paralichthys orbignyanus in captivity was done in 2002. Morphological description of the different stages of development (yolk sac, drifting, premetamorphic, metamorphic, postmetamorphic larvae and juvenile) are presented, including their duration (days post-hatching), degree-days and feeding schedule. Also, abnormalities in both pigmentation and eye-migration were characterized. Larval developmental stages described in this study for P. orbignyanus follow those described for P. olivaceus. At 40 days post-hatching (dph) and 798 ºC days, juveniles measured in average 11.6±0.5 mm. Mean survival rate after 142 dph was 49.7%. More than half of the total juveniles obtained (59.1%) were albino, whereas 15.5% were normally pigmented and 13.2% showed abnormal eye migration (dextral or reversed). Development of larval culture methods and quality control of batches will allow the optimization of P. orbignyanus juvenile mass production.Additional key words: eye-migration, flatfish, juvenile abnormalities, fish larval development, fish larval rearing. ResumenTécnica de cultivo larvario y control de calidad en juveniles del lenguado Paralichthys orbignyanus (Valenciennes, 1839) en ArgentinaLos lenguados de la Familia Paralichthydae constituyen un recurso muy importante en el Atlántico Sur debido a su abundancia, calidad de su carne, alto precio en el mercado e incremento del esfuerzo pesquero. En Argentina, la primera producción masiva de juveniles del lenguado Paralichthys orbignyanus en cautiverio se realizó con éxito en el año 2002. Se decribe la morfología de los diferentes estadios de desarrollo de esta especie (larvas vitelina, pelágica, premetamórfica, metamórfica, postmetamórfica, y juvenil), relacionándolos con la duración de los mismos (días posteriores a la eclosión), grados días y el esquema alimentario aplicado. Además se caracterizan las anormalidades pigmentarias y aquéllas relacionadas con la migración ocular. Los estadios del desarrollo larvario de P. orbignyanus son similares a los descriptos para P. olivaceus. A los 40 días posteriores a la eclosión y 798 grados días, se alcanzó el estadio de juvenil con una talla media de 11,6±0,5 mm. La supervivencia promedio obtenida al cabo de 142 días de cultivo fue de 49,7%. Más de la mitad de los juveniles obtenidos (59,1%) fueron albinos, mientras que el 15,5% presentó pigmentación normal. El 13,2% de la camada mostró migración del ojo al lado derecho del cuerpo (individuos dextro). El desarrollo de métodos de cultivo larvario y el control de calidad de las camadas obtenidas, permitirá la optimización de la producción masiva de juveniles de P. orbignyanus.Palabras clave adicionales: anormalidades larvales, cultivo de larvas, desarrollo larvario, migración ocular, pez plano.Abbreviations used: DHA (docosahexaenoic acid), dph (days po...

Early development and Juvenile Culture Technique of Speckled Flounder,Paralichthys woolmani(Jordan & Williams, 1897) under ambient seawater

“…The yolk‐sac was completely absorbed on 2–3 DPH. Larval development in P. woolmai was similar to those described for P. orbignyanus (López et al., ) and P. olivaceus (Wang, Guo, Zhao, Liu, & Lu, ). In agreement with our results, juvenile stage was reached after 30 DPH at 24.1°C.…”

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“…Our results agree with Aritaki and Seikai (2004), who stated that hatchery-reared brown sole Pseudopleuronectes herzensteini have a high probability of developing morphological metamorphosis-related abnormalities closely linked to rearing temperature. Reversed asymmetry has also been reported to be common in reared flatfish by López et al (2009), although the causes of this phenomenon are not known (Benetti et al, 2001). In some pleuronectid species, such as P. herzensteini, P. yokohamae, P. cornutus and Verasper variegatus, reversals have been frequently observed in hatcheryreared individuals, although rarely seen in wild fish (Hubbs and Hubbs, 1945;Goto, 2009).…”

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“…Sinistral form of P. flesus luscus juveniles represented as 29,6% in this research. The causes of reverse phenomenon are not known (López et al, 2009).…”